. >> so, you're perfectly happy with his demeanor and energy level tonight? >> what i'm happy with is the path he wants to lead this country on. >> hello, colorado! >> reporter: even while cheering the president at a rally today, his supporters seemed puzzled by his debate performance. >> i didn't know quite what was going on as far as maybe he's dealing with some crisis in the middle east. >> reporter: in states like colorado and ohio, undecided voters nbc gathered to watch the debate say they saw something new. >> governor romney just sort of stepped up in terms of being something new. >> it did change the way i thought about him. >> reporter: it was the most heavily tweeted item in history. even big bird was a hot topic. if mitt romney wins, this is what i'll be forced to do. this tidal wave of real time commentary on social media is just another uncontrollable factor that campaigns struggle to deal with as they try to get their messages out. >> john yang samupling the reanchors. our chief white house correspondent, chuck todd, traveling with the president